gibus

[jahy-buh s] /ˈdʒaɪ bəs/
noun, plural gibuses.
1.
Also called gibus hat.
Origin
1840-50; named after Gibus, 19th-century Frenchman, its inventor
British Dictionary definitions for gibus

gibus

/ˈdʒaɪbəs/
noun
1.
another name for opera hat
Word Origin
C19: named after Gibus, 19th-century Frenchman who invented it